Update python wheel requirement dependency

Only specify the requirements to build the ot_python_wheels repo, but
the derived ot_python_deps for pip_install still depends on the
generated sanitized list, so it can support airgapped mode.

Change-Id: I9c734acf56d699f4f478dc2ba8fbb80f4055ca59

third_party/python/pip.bzl

diff --git a/third_party/python/pip.bzl b/third_party/python/pip.bzl
index 0a4bf65..32eb1c4 100644
--- a/third_party/python/pip.bzl
+++ b/third_party/python/pip.bzl
@@ -2,8 +2,8 @@
 # Licensed under the Apache License, Version 2.0, see LICENSE for details.
 # SPDX-License-Identifier: Apache-2.0
 
-load("@rules_python//python:pip.bzl", "pip_install")
 load("@python3//:defs.bzl", "interpreter")
+load("@rules_python//python:pip.bzl", "pip_install")
 
 _WHEEL_BUILD_FILE_CONTENTS = """\
 package(default_visibility = ["//visibility:public"])
@@ -134,7 +134,7 @@
     pip_install(
         name = "ot_python_deps",
         python_interpreter_target = interpreter,
-        requirements = "@lowrisc_opentitan//:sanitized_requirements.txt",
+        requirements = "@ot_python_wheels//:sanitized_requirements.txt",
         find_links = "@ot_python_wheels//:all_wheels",
         extra_pip_args = ["--no-index"],
     )